植物内源性多胺的LC-MS分析方法研究

多胺是一类重要的植物激素，其内源性含量信息的获取对阐明其分子作用机理从而促进育种及农业生产具有重要意义。然而，植物中多胺的分析受到诸多因素的限制，如，植物基质复杂，多胺反相色谱保留弱，质谱响应重现性差。本项目拟合成葫[6]环联脲修饰的磁性纳米颗粒作为萃取介质，利用多胺与葫[6]环联脲间的主客体化学作用对多胺进行选择性富集纯化；引入同位素标记技术，以醛类标记试剂衍生多胺，改善多胺的反相色谱保留及质谱灵敏度，并获得廉价易得的内标以校正质谱信号波动；最终建立基于超分子化学磁固相萃取-稳定同位素标记技术的稳定、可靠、高灵敏的植物中多胺分析方法，以此作为分析手段初步研究镉胁迫水稻中内源性多胺水平的时空分布。

Polyamines are a group of plant growth regulators related to cell development and plant responses to environmental challenges. The information of endogenous polyamine levels in plant is helpful to elucidate the underlying mechanism of polyamines. Whereas, polyamines analysis is hampered by the complicated plant matrix, their weak retention on reversed-phase liquid chromatography and the poor reproducibility of MS signal. To overcome the above-mentioned obstacles, the current project focuses on LC-MS method for the determination of endogenous polyamines in plant tissues, involved in the sample preparation, chemical derivatization and LC-MS detection of polyamine. For sample preparation, Cucurbit[6]uril (CB[6]) modified magnetic nanoparticles will be prepared to selectively extract polyamines from plant tissues based on host-guest chemistry of CB[6] and polyamines. To improve chromatographic retention and correct the MS signal variations, a pair of isotope labeled aldehydes will be employed to derive polyamines: “light” aldehyde was used to label polyamines extracted and purified from plant tissues, and “heavy” aldehyde was employed to label pure polyamines as internal standard for LC-MS analysis. Therefore, by the combination of the magnetic solid phase extraction based on the supramolecular chemistry, stable isotope labeling, and LC-MS, a selective, sensitive and reliable analytical method for determination of endogenous polyamines in plant tissues will be established, which will further be employed to investigate the spatiotemporal information of endogenous polyamine in rice under Cd stress .